Search

Edge computing brings artificial intelligence algorithms and graphics processing units closer to data sources, making autonomy and energy-efficient processing vital for their design. Approximate computing has emerged as a popular strategy for energy-efficient circuit design, where the challenge is to achieve the best tradeoff between design efficiency and accuracy. The essential operation in artificial intelligence algorithms is the general matrix multiplication (GEMM) operation comprised of matrix multiplication and accumulation. This paper presents an approximate general matrix multiplication (AGEMM) unit that employs approximate multipliers to perform matrix–matrix operations on four-by-four matrices given in sixteen-bit signed fixed-point format. The synthesis of the proposed AGEMM unit to the 45 nm Nangate Open Cell Library revealed that it consumed only up to 36% of the area and 25% of the energy required by the exact general matrix multiplication unit. The AGEMM unit is ideally suited to convolutional neural networks, which can adapt to the error induced in the computation. We evaluated the AGEMM units’ usability for honeybee detection with the YOLOv4-tiny convolutional neural network. The results implied that we can deploy the AGEMM units in convolutional neural networks without noticeable performance degradation. Moreover, the AGEMM unit’s employment can lead to more area- and energy-efficient convolutional neural network processing, which in turn could prolong sensors’ and edge nodes’ autonomy.

Simple Summary Honey bee colonies collect pollen from plants as a source of nutrients. Diverse diets comprising pollen from many different plant species are beneficial for honey bee colony health, because they contain a greater diversity of nutrients than monofloral diets of one plant species only. Here, we present the results of the COLOSS “CSI Pollen” study on the diversity of pollen collected by honey bee colonies. In this study, beekeepers acted as citizen scientists sampling and analyzing pollen collected by their own colonies. As a simple measure of diversity, beekeepers determined the number of different colors found in pollen samples that were collected in a coordinated and standardized way. The support of 750 beekeepers allowed the collection of information about almost 18,000 pollen samples from many European countries. We found that the pollen samples consistently comprised approximately six different colors in total, of which four colors were abundant. ‘Urban’ habitats or ‘artificial surfaces’ were associated with higher pollen color diversity. This investigation highlights seasonal- and land-use-related differences in the pollen supply for honey bees, which affects beekeeping and pollinator health. Determining pollen colors is a simple, useful technique for beekeepers to estimate pollen diversity. Abstract A diverse supply of pollen is an important factor for honey bee health, but information about the pollen diversity available to colonies at the landscape scale is largely missing. In this COLOSS study, beekeeper citizen scientists sampled and analyzed the diversity of pollen collected by honey bee colonies. As a simple measure of diversity, beekeepers determined the number of colors found in pollen samples that were collected in a coordinated and standardized way. Altogether, 750 beekeepers from 28 different regions from 24 countries participated in the two-year study and collected and analyzed almost 18,000 pollen samples. Pollen samples contained approximately six different colors in total throughout the sampling period, of which four colors were abundant. We ran generalized linear mixed models to test for possible effects of diverse factors such as collection, i.e., whether a minimum amount of pollen was collected or not, and habitat type on the number of colors found in pollen samples. To identify habitat effects on pollen diversity, beekeepers’ descriptions of the surrounding landscape and CORINE land cover classes were investigated in two different models, which both showed that both the total number and the rare number of colors in pollen samples were positively affected by ‘urban’ habitats or ‘artificial surfaces’, respectively. This citizen science study underlines the importance of the habitat for pollen diversity for bees and suggests higher diversity in urban areas.

Three-dimensional (3D) magnetic resonance microscopy (MRM) is a modality of magnetic resonance imaging (MRI) optimized for the best resolution. Metamorphosis of the Carniolan worker honey bee (Apis mellifera carnica) was studied in vivo under controlled temperature and humidity conditions from sealed larva until the emergence of an adult. The 3D images were analyzed by volume rendering and segmentation, enabling the analysis of body, tracheal system and gastrointestinal tract through volume time course. Fat content sensitivity enabled the analysis of flight muscles transformation during the metamorphosis by the signal histogram and gray level co-occurrence matrix (GLCM). Although the transformation during metamorphosis is well known, MRM enables an alternative insight to this process, i.e., 3D in vivo which has relatively high spatial and temporal resolutions. The developed methodology can easily be adapted for studying metamorphosis of other insects or any other incremental biological process on a similar spatial and temporal scale.

The extensive production of zinc oxide (ZnO) nanomaterials (NMs) may result in high environmental zinc burdens. Honeybees need to have special concern due to their crucial role in pollination. Our previous study indicated that low concentrations of ZnO NMs, corresponding to 0.8 mg Zn/mL, have a neurotoxic potential for honeybees after a 10-day oral exposure. Present study was designed to investigate the effect of a short, dietary exposure of honeybees to ZnO NMs at concentrations 0.8-8 mg Zn/mL on consumption rate, food preference, and two enzymatic biomarkers-a stress-related glutathione S-transferase (GST) and the neurotoxicity biomarker acetylcholinesterase (AChE). Consumption rate showed a tendency toward a decrease feeding with the increasing concentrations of ZnO NMs. None of Zn NMs concentrations caused alterations in mortality rate and in the activities of brain GST and AChE. To investigate if there is an avoidance response against Zn presence in food, 24-h two-choice tests were performed with control sucrose diet versus sucrose suspensions with different concentrations of ZnO NMs added. We demonstrated that honeybees prefer ZnO NMs ZnO NMs containing suspensions, even at highest Zn concentrations tested, compared with the control diet. This indicates that they might be able to perceive the presence of ZnO NMs in sucrose solution. Because honeybees feed frequently the preference towards ZnO NMs might have a high impact on their survival when exposed to these NMs.

The high annual production and use of cerium(IV) oxide nanoparticles (nCeO2s) may lead to their atmospheric release and substantial deposition on plants. This poses a potential threat to pollinators. We investigated the effects of nCeO2-spiked food (2–500 mg L−1) on summer and winter honeybees (Apis mellifera carnica) after chronic 9 days' oral exposure. Acetylcholinesterase (AChE) and glutathione S-transferase (GST) activities were measured in different body compartments (heads, thoraces, and haemolymph). The activity of AChE was assessed in salt-soluble (SS) (containing soluble and membrane AChE) and detergent-soluble (DS) (predominantly membrane-bound AChE) fractions. Exposure of honeybees to nCeO2-spiked food had no significant effects on survival up to 500 mg L−1 (

The parasitic mite Varroa destructor is a threat to beekeeping colonies. Among naturally derived acaricides, the monoterpenoid essential oil compound thymol is used in beekeeping for varroa mite control, but adverse impacts on honeybees has been already documented. Carvacrol, another monoterpenoid, also has a high acaricidal potential and could thus be promising for regular use in beekeeping, but information is scarce regarding the effects of prolonged systemic administration of carvacrol on honeybees. In this study, we evaluate and compared the sublethal effects of long term consumption of carvacrol and thymol on Carnolian honeybee workers (Apis mellifera carnica). Survival and feeding rate were determined preliminary to assess sublethal concentrations. The sublethal effects were analysed by the activity of the acetylcholinesterase (AChE), enzyme involved in the control of neurotransmission, and the activity of detoxifying enzyme glutathione S-transferase (GST) in heads and thoraces. We found that, thymol and carvacrol, caused mortality only at the highest concentrations tested, 1% and 5% respectively. As demonstrated by others, both substances could be effective against varroa at concentrations ten times lower than those causing significant honeybee mortality. However, we demonstrated sublethal effects at the 0.05% carvacrol and thymol exposure concentrations evidenced as increased activity of AChE and GST in the honeybee heads. In conclusion, prolonged treatment with thymol and carvacrol affects bee nervous system and induce detoxification processes possibly resulting in a limited use for acaricidal purposes. We postulate that under the same chronic exposure conditions carvacrol and thymol will have similar sublethal effects on honeybees.

The Carniolan honey bee, Apis mellifera carnica, is a Slovenian autochthonous subspecies of honey bee. In recent years, the country has recorded an annual loss of bee colonies through mortality of up to 35%. One possible reason for such high mortality could be the exposure of honey bees to xenobiotic residues that have been found in honey bee and beehive products. Acaricides are applied by beekeepers to control varroosis, while the most abundant common agricultural chemicals found in honey bee and beehive products are fungicides, which may enter the system when applied to nearby flowering crops and fruit plants. Acaricides and fungicides are not intrinsically highly toxic to bees but their action in combination might lead to higher honey bee sensitivity or mortality. In the present study we investigated the molecular immune response of honey bee workers at different developmental stages (prepupa, white-eyed pupa, adult) exposed to the acaricide coumaphos and the fungicide prochloraz individually and in combination. Expression of 17 immune-related genes was examined by quantitative RT-PCR. In treated prepupae downregulation of most immune-related genes was observed in all treatments, while in adults upregulation of most of the genes was recorded. Our study shows for the first time that negative impacts of prochloraz and a combination of coumaphos and prochloraz differ among the different developmental stages of honey bees. The main effect of the xenobiotic combination was found to be upregulation of the antimicrobial peptide genes abaecin and defensin-1 in adult honey bees. Changes in immune-related gene expression could result in depressed immunity of honey bees and their increased susceptibility to various pathogens.

The honey bee is among most important pollinators threatened by environmental pollution, pest control and potentially, by products of nanotechnologies. The aim of the current study was an analysis of the neurotoxic potential of ingested zinc oxide nanomaterials (ZnO NMs) or zinc ions (Zn(2+)) on honey bees. We analysed a variety of biomarkers, including metabolic impairment, feeding rate, and survival, as well as the activities of a stress-related enzyme glutathione S-transferase, and the neurotoxicity biomarker acetylcholinesterase. Acetylcholinesterase activity was found to be elevated in bees exposed to either of the tested substances. In addition, we observed increased feeding rate in the group treated with Zn(2+) but not with ZnO NMs or control group. The observed effects we relate primarily to Zn(2+) ions. Here we provide evidence that zinc ions either originating from Zn salt or Zn-based NPs have a neurotoxic potential and thus might contribute to colony survival.

Organophosphate pesticide diazinon is a specific inhibitor of acetylcholinesterase (AChE), which is a common neurotoxicity biomarker in environmental studies. In honeybees, AChE exists in two forms having different physiological roles, one existing as a soluble form and the other as membrane-bound. In most studies AChE activity has been analysed without paying considerable attention to different forms of AChE. In this study, we exposed honeybees Apis mellifera carnica for 10days to diazinon via oral exposure and analysed the total AChE activities in salt soluble (SS) and detergent soluble (DS) fractions. We assumed that SS fraction would preferentially contain the soluble AChE, but the DS fraction would contain only membrane AChE. On the contrary, our results showed that SS and DS fractions both contain soluble and membrane AChE and the latter has considerably higher activity. Despite this we obtained a differential response of AChE activity in SS and DS fractions when exposed to diazinon. The head/thorax AChE activity in DS fraction decreased, while the head/thorax AChE activity in SS fraction increased at sublethal concentrations. The AChE activity in honeybee hemolymph shown here for the first time is a salt soluble enzyme. Its activity remained unaltered after diazinon treatment. In conclusion, we provide evidence that varying results regarding AChE activity alterations upon stressor exposure are obtained when extracted through different procedures. In further environmental studies with honeybees this differential response of AChE activity should be given considerable attention because this affects the outcome of ecotoxicity study.

Varroa destructor is one of the most common parasites of honey bee colonies and is considered as a possible co-factor for honey bee decline. At the same time, the use of pesticides in intensive agriculture is still the most effective method of pest control. There is limited information about the effects of pesticide exposure on parasitized honey bees. Larval ingestion of certain pesticides could have effects on honey bee immune defense mechanisms, development and metabolic pathways. Europe and America face the disturbing phenomenon of the disappearance of honey bee colonies, termed Colony Collapse Disorder (CCD). One reason discussed is the possible suppression of honey bee immune system as a consequence of prolonged exposure to chemicals. In this study, the effects of the neonicotinoid thiamethoxam on honey bee, Apis mellifera carnica, pupae infested with Varroa destructor mites were analyzed at the molecular level. Varroa-infested and non-infested honey bee colonies received protein cakes with or without thiamethoxam. Nurse bees used these cakes as a feed for developing larvae. Samples of white-eyed and brown-eyed pupae were collected. Expression of 17 immune-related genes was analyzed by real-time PCR. Relative gene expression in samples exposed only to Varroa or to thiamethoxam or simultaneously to both Varroa and thiamethoxam was compared. The impact from the consumption of thiamethoxam during the larval stage on honey bee immune related gene expression in Varroa-infested white-eyed pupae was reflected as down-regulation of spaetzle, AMPs abaecin and defensin-1 and up-regulation of lysozyme-2. In brown-eyed pupae up-regulation of PPOact, spaetzle, hopscotch and basket genes was detected. Moreover, we observed a major difference in immune response to Varroa infestation between white-eyed pupae and brown-eyed pupae. The majority of tested immune-related genes were upregulated only in brown-eyed pupae, while in white-eyed pupae they were downregulated.

Slovene heritage in beekeeping is based on knowledgeable bee management practice documented well in 18th century. Well described mating biology of honeybees was first detailed description of specific behavior of honeybees based on observation in well know subspecies of Carniolan bee. Later in 20th century special focus was on dance communication, which was described by von Frisch (1965) as a dance language. In the work alone it was not described as a special cognitive capability of the honeybees but rather instinctive highly specialized behavior pattern. From original work to nowadays many detailed studies of the dance communication were published and also used as a tool to study orientation and learning during foraging behavior. New concept have been involved, especially in sense of new views and methods in cognitive science. How much cognition is involved in foraging behavior of honeybees depends on how wide we accept definition of cognition. Key words : Apis mellifera carnica , communication, waggle dance, recruitment, foraging, information transfer Izvlecek Slovenska cebelarska dediscina temelji na dobrem poznavanju cebelarske prakse, ki je bila dokumentirana že v 18. stoletju. Dobro opisana biologija parjenja medonosne cebele je bil prvi podroben opis posameznega vedenja medonosne cebele temeljece na opazovanjih dobro poznane podvrste kranjske cebele. Kasneje v 20. stoletju je bila posebna pozornost na plesnem sporazumevanju cebel, ki jo je opisal von Frisch (1965) kot cebelji jezik. V samem njegovem delu sicer ni bilo opisano kot posebna razumska zmožnost cebel ampak bolj kot mocno usmerjen nagonski vedenjski vzorec. Od originalnega dela pa do danes je bilo objavljenih veliko podrobnih raziskav plesnega sporazumevanja in tudi uporabljeno kot orodje za raziskavo orientacije in ucenja med pasnim vedenjem. Razvili so se novi koncepti, se posebej v smislu novih pogledov in metod v kognitivni znanosti. Koliko razuma je vkljuceno v pasno vedenje cebel je odvisno od tega, kako na siroko sprejmemo definicijo razuma. Kljucne besede : Apis mellifera carnica , sporazumevanje, zibajoci ples, novacenje, pasa, prenos informacije

A worker-queen contact in the retinue of the honeybee (Apis mellifera) enables transfer of queen pheromones to workers. Behaviours of workers attending the queen and post-contact behaviours were recorded. The most commonly observed activities of workers in retinue were licking and antennating the queen. Those activities were interrupted with bouts of self-grooming, which was the most frequently observed activity of licking attendants. Immediately after leaving, the queen workers which had licked the queen, self-groomed longer and more frequently than workers which had antennated the queen. Licking post-retinue workers walked significantly faster and rested less frequently than palpating post-retinue workers, which suggest that licking attendants are most effective in the pheromone transfer accomplished by accidental encounters with other nestmates.

Mature honeybees (Apis mellifera L.) old enough to forage (>3 weeks) were segregated into three activity groups: waggle dancers (active foragers), followers of the dancers (potential recruits) and resting bees (not involved in foraging). Dopamine (DA) pathways in the brain of honeybees seemed to be involved in regulation of forager recruitment. Brain DA and N-β-alanyldopamine (NBAD) levels in the dancers were always higher than in followers, and an increased number of dancers was observed after feeding the colony dihydroxy-phenylalanine (DOPA). Dopamine is hypothesized to modulate the neural activity in the calyx of the mushroom bodies related to recruitment behavior. No consistant effect of octopamine (OA) or serotonin (5HT) on recruitment behavior was observed. Levels of all biogenic amines were strongly effected by season and day-to-day whether changes. Some diurnal changes were also observed.

In this study, the effects of ethanol on honey bee social communication and behavior within the hive were studied to further investigate the usefulness of honey bees as an ethanol-abuse model. Control (1.5 M sucrose) and experimental (1.5 M sucrose, 2.5% w/v ethanol) solutions were directly administered to individual forager bees via proboscis contact with glass capillary tubes. The duration, frequency, and proportion of time spent performing social and nonsocial behaviors were the dependent variables of interest. No differences in the relative frequency or proportion of time spent performing the target behaviors were observed. However, ethanol consumption significantly decreased bouts of walking, resting, and the duration of trophallactic (i.e., food-exchange) encounters. The results of this study suggest that a low dose of ethanol is sufficient to disrupt both social and nonsocial behaviors in honey bees. In view of these results, future behavioral-genetic investigations of honey bee social behavior are encouraged.

SUMMARYThe behaviour of bees surrounding a dancing honey bee (Apis mellifera) was studied, using two colonies in observation hives in a shaded part of an apiary. Video recordings and macrophotography were used to view an area of the dance field. Two distinct behaviours were recognized: that of followers and that of attendants. The attendants stood around the dance field with their antennae stretched towards the dancer, and only occasionally moved with the dancer. Followers continuously ran with the dancer, keeping their heads within the border of the dancer's figure-eight path at all times. The angle between the body of the follower and that of the dancer was 90° during most of the dance, except at the exit of the waggle run. At that time the follower had to cross over to the opposite side of the dancer. The distance between the head of the follower and the dancer's body was nearly always smaller (1 758 cases out of a total of 1 882) than the length of an extended antenna. During the return run the follow...

The objective of this study was to find out whether Porcellio scaber discriminates against Cd-contaminated food. The foraging behavior in animals offered uncontaminated and Cd-contaminated food simultaneously was quantified for 48-h employing computer-aided video tracking. To see whether the isopods' selection of less contaminated food could diminish the influence Cd on food consumption, growth, metal assimilation, moulting and mortality, Cd-dosed food (20, 45, 200 and 450 mg kg(-1) dry weight) was offered together with untreated food for 3 weeks. Data from the video tracking experiments revealed that animals visited Cd-dosed food as often as untreated food, but spent much less time near Cd-dosed food. Discrimination against Cd-contaminated food increased with previous experience with contaminated food and/or with increased Cd body burden. In 3 weeks exposure uncontaminated food preference rose with time of exposure and cadmium concentration in food and reached a maximal preference ratio of 65% (untreated food): 35% (Cd-dosed food). The decreased consumption of Cd-dosed food was compensated by the increased consumption of control food. Cadmium body burden increased with time of exposure and cadmium concentration in food consumed, while the influence of Cd on food consumption, growth and moulting was diminished.

Experiments are designed to assess whether free-flying honey bees have an aversion to an ethanol solution when given a choice between targets containing an ethanol solution in sucrose or sucrose only. Animals given a choice between a 1% ethanol solution and sucrose only show no aversion to the ethanol solution either in acquisition or extinction. Honey bees given a choice between a 5% ethanol solution and sucrose only show no differences in the initial choice of targets but some bees do switch over to the sucrose-only target. Performance during extinction indicates that bees landed on the previously reinforced sucrose-only target more than the target previously containing the 5% ethanol solution. An experiment in which bees were given a single 5% ethanol target showed that of 20 bees, 11 returned for the entire 12 trials of the experiment. All bees returned at least 6 times to the 5% ethanol target. Additional experiments were run on harnessed foragers in a palatability study of alcoholic beverages consumed by humans. The results of the palatability experiment indicate that in general, bees prefer more sweet drinks with less alcohol.

We observed social grooming behavior in the Carniolan bee, Apis mellifera carnica. Bouts of grooming lasted up to 45 s, and were directed to the wing axis (44.6%), the petiolus (18%) and the sternite regions of abdomen (2.8%) of the receiving bee (41 bees). During grooming, the receiving bees held their wings perpendicular to the body axis. Groomer bees most often cleaned those body parts which could not be reached during self-cleaning by receiving bees. During 18% of the grooming time, groomer bees cleaned their own mouth parts and antennae. The grooming behavior removed dust and pollen from the wing bases and petiolus and realigned the body hairs. No attempts to remove Varroa mites were observed during self-cleaning or social grooming behavior

Juvenile hormone (JH) synthesis was higher in followers than in dancers, which suggests that higher JH levels in followers might be an internal motivational stimulus to induce them to leave the hive to search for food. The positive correlation of in vitro JH synthesis rate and alpha-glucosidase activity in the hypopharyngeal gland suggests that JH is involved in the reprogramming of the hypopharyngeal gland from producing larval food (immature adults) to production of alpha-glucosidase in mature adults.

The quality control of the honey botanical origin is still an open question. In recent years, the honey authentication has been focused toward identifying volatile markers of plant origin. Honey volatiles results from nectar or honeydew composition, bees actiyity or from industrial processing. Isolated volatiles show strong variability according to the extraction procedure. Therefore two-way approach to the honey volatiles profiling using both headspace solid-phase microextraction (HS-SPME) and ultrasonic solvent axtraction (USE) followed by GC-MS is important to obtain complete profile of volatile and semi-volatile compounds. The results of HS-SPME and USE volatiles profiling of Mentha spp. honey, Salix spp. honey and different honeydews will be presented with emphasis to found potential botanical markers for quality control.

Oak tree (Quercus frainetto Ten.) is distributed around southeast Europe and Asia Minor, while the western border is in Požega valley, Croatia. Oak honeydew honey has specific way of production. Sweet sap with foam appearance, which is formed at the place where the green acorns were discarded, is gathered by the bees and processed into dark honey. Specific way of production results in specific physiochemical characteristics of this honeydew honey. Objective of this preliminary study was to determine antioxidant capacity, total polyphenol content and physicochemical characteristics of oak honeydew honey. Melissopalynological analysis was performed and following physicochemical characteristics were determined: moisture, electrical conductivity, HMF content, diastase activity, specific rotation and sugar profile. Colour was determined by Lovibond Honey ColorPod. Antioxidant capacity was determined by FRAP (Ferric Reducing Antioxidant Power) and DPPH (2, 2-diphenyl-1-picrylhydrazyl) methods, and total polyphenol content by modified Folin-Ciocalteu method. The results showed high antioxidant capacity and total polyphenol content as well as atypical negative values of specific rotation.